diff --git a/CHANGELOG.md b/CHANGELOG.md
index b02b7934..eb1643fe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ Fixed issues: <https://github.com/eclipse/lsp4j/milestone/28?closed=1>
 
 Breaking API changes:
 
+ * LSP4J now requires Java 11 to build and run. This can be observed in the japicmp
+   report which says class file format version changed from  52.0 to 55.0.
+   <https://github.com/eclipse/lsp4j/issues/547>.
+
 Nightly japicmp report: <https://download.eclipse.org/lsp4j/builds/main/japicmp-report/>
 
 ### [v0.20.1 (February 2023)](https://github.com/eclipse/lsp4j/releases/tag/v0.20.1)
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 38f4dfeb..2b644202 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,6 +1,6 @@
 # Contribution Guide
 
-The project is build with Gradle and written in Java 8.
+The project is build with Gradle and written in Java 11.
 
 To start working on it simply clone and run `./gradlew build`. See the section [below](#Eclipse) on building and editing with Eclipse for step-by-step instructions.
 
diff --git a/gradle/java-compiler-settings.gradle b/gradle/java-compiler-settings.gradle
index 9a641fdd..f5d9f61f 100644
--- a/gradle/java-compiler-settings.gradle
+++ b/gradle/java-compiler-settings.gradle
@@ -10,7 +10,7 @@
  * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
  ******************************************************************************/
 
-sourceCompatibility = '1.8'
+sourceCompatibility = '11'
 
 tasks.withType(Javadoc) {
 	options.addStringOption('Xdoclint:none', '-quiet')
diff --git a/gradle/manifest-gen.gradle b/gradle/manifest-gen.gradle
index 34c12880..692a6f80 100644
--- a/gradle/manifest-gen.gradle
+++ b/gradle/manifest-gen.gradle
@@ -21,7 +21,7 @@ def qualifiedVersion = baseVersion + '.v' + buildTime
 jar.bnd (
 	'Bundle-Version': qualifiedVersion,
 	'Bundle-Vendor': 'Eclipse LSP4J',
-	'Bundle-RequiredExecutionEnvironment': 'JavaSE-1.8',
+	'Bundle-RequiredExecutionEnvironment': 'JavaSE-11',
 	"-exportcontents": "org.eclipse.lsp4j.*",
 	"-savemanifest": "$buildDir/tmp/bnd/MANIFEST.MF",
 )
diff --git a/org.eclipse.lsp4j/build.gradle b/org.eclipse.lsp4j/build.gradle
index fadb0481..f36dba4e 100644
--- a/org.eclipse.lsp4j/build.gradle
+++ b/org.eclipse.lsp4j/build.gradle
@@ -13,8 +13,8 @@
 ext.title = 'LSP4J'
 description = 'Java bindings for the Language Server Protocol'
 
-sourceCompatibility = '1.8'
-targetCompatibility = '1.8'
+sourceCompatibility = '11'
+targetCompatibility = '11'
 
 dependencies {
 	compileOnly project(":org.eclipse.lsp4j.generator")
diff --git a/releng/build.Jenkinsfile b/releng/build.Jenkinsfile
index f722a5ec..d1b91599 100644
--- a/releng/build.Jenkinsfile
+++ b/releng/build.Jenkinsfile
@@ -7,7 +7,7 @@ pipeline {
   }
   tools {
     maven 'apache-maven-latest'
-    jdk 'oracle-jdk8-latest'
+    jdk 'adoptopenjdk-hotspot-jdk11-latest'
   }
   options {
     timestamps()
diff --git a/releng/release-eclipse.Jenkinsfile b/releng/release-eclipse.Jenkinsfile
index 79e3260d..a7f24d22 100644
--- a/releng/release-eclipse.Jenkinsfile
+++ b/releng/release-eclipse.Jenkinsfile
@@ -7,7 +7,7 @@ pipeline {
   }
   tools {
     maven 'apache-maven-latest'
-    jdk 'oracle-jdk8-latest'
+    jdk 'adoptopenjdk-hotspot-jdk11-latest'
   }
   options {
     timestamps()